Variable tuning condenser



y 7, 1936. J. ANTONIETTA I 2,046,994

VARIABLE TUN I NG CONDENSER Original Filed March 28, 1933 /5---J J i 47 ATTORNEY Patented July 7, 1936 UNITED STATES PATENT OFFICE 663,120, now Patent No. 1,972,510, dated Septemben 4, 1934. Divided and this application November 3, 1933, Serial No. 696,472

8 Claims.

This invention relates to variable condensers, and particularly to devices of this character used for tuning as in radio apparatus.

One object of the invention is to devise a variable condenser having an improved mounting or shaft construction for the rotor plates, whereby the rigidity of the rotor plate is increased, lightness in the weight of the shaft maintained, or rendered less than the weight of the usual round or solid shaft, and which shaft can be formed from sheet material, if desired.

Another object of the invention is to construct a variable condenser having improved similar means for mounting the shaft at opposite ends thereof; improved means for mounting and insulating the stator plates; improved means for reenforcing the frame of the condenser; and improved closure means for the condenser; the above feature being adapted for utilization in any desired arrangement or combination.

A further object of the invention is to furnish an improved condenser having few and simple parts, and which is compact and inexpensive in construction, convenient to make and use, and durable, reliable, and efficient in operation.

This is a. divisional application based on my Patent No. 1,972,510, issued September 4, 1934.

Other objects and advantages of the invention will become apparent as the specification proceeds.

With the aforesaid objects in view, the invention consists in the novel combinations and arrangements of parts hereinafter described in their preferred embodiments, pointed out in the subjoined claims, and illustrated on the annexed drawing, wherein like parts are designated by the same reference characters throughout the several views.

In the drawing:

Figure 1 is a view in front elevation of a device embodying the invention with parts removed to show the internal construction.

Fig. 2 is a view in side elevation thereof.

Fig. 3 is a top plan view thereof, with parts removed, and other parts being in section.

Fig. 4 is a longitudinal sectional view of the shaft taken on line 44 of Fig. 3.

Fig. 5 is a transverse sectional viewof the shaft taken on line 5-5 of Fig. 3 and showing a condenser rotor plate in dot-dash lines.

Fig. 6 is a horizontal sectional view taken on line 56 of Fig. 2.

Fig. 7 is a fragmentary plan view of a rotor condenser plate.

Fig. 8 is a fragmentary horizontal sectional view of the shaft taken on line 88 of'Fig. 4.

The advantages of the invention as here outlined are best realized when all of its features and instnimentalities are combined in one and the same structure, but useful devices may be produced embodying less than the whole.

It will be obvious to those skilled in the art to which this invention appertains, that the same may be incorporated in several different constructions. The accompanying drawing, therefore, is submitted merely as showing the preferred exemplification of the invention.

Referring in detail to the drawing, l0 denotes a device embodying the invention. The same may include a frame having a plurality of parallel end plates ll, l2 of similar form, and whose upper edges l3 may be are shaped to conform to the shape of the rotor plates of the condenser. Interconnecting said end plates there may be a one piece frame member of generally U shaped form, and having a bottom plate section I4 and upright side plate sections [5 that may be exactly alike. somewhat inward of the adjacent side edges l6 of the end plates, and the side sections I5 may have marginal outwardly bent flanges I'l extending therealong to the edges IS. The frame members l4, l5 may lie in abutment between the end plates, and may be secured thereto as by the usual lugs I8 passed through suitable openings in the end plates and deformed'or headed to form a strong interconnection. If the condenser is of a double section type, a plate 19 may be provided intermediate of and parallel to the end plates and of generally similar shape therewith. Said intermediate plate may be secured in place in any suitable manner as by lugs I8 engaging frame section l4, and it may be undercut to lie between frame sections I 5 and conform to the flanges H, as will be obvious. To provide a closure for the condenser frame or housing, a cover 20 may be utilized, and which may consist of an arcuate resilient or flexible sheet of metal adapted to seat on the curved edges I 3 of the end plates H, l2, and having longitudinal parallel lips 2! adapted to be snapped under the flanges I! for retaining the cover in place.

For mounting the device on the chassis of a radio apparatus, the frame section l4 may have bosses 22 downwardly struck to the plane of the lower edges 23 of the end plates, and threaded as at 24 for receiving screws. Should there be any irregularity in the chassis or frame, the latter would be sprung by the tension of the screws at The frame member may be spaced 28 and hence the frame would become distorted and the spacing between the condenser plates affected, as hereinafter more particularly tiescribed. Such distortion, however, is prevented 5 by the flanges i l which afford a strong and simple reenforcement where it is most needed.

The variable condenser includes a stator having one or more plates 25 and a rotor having one or more plates 26 suitably arranged in alternating .10 but spaced relation, and being each in the form of a sector or semicircle, and disposed in parallel planes, whereby, on angularly moving the rotor, the capacity of the condenser is varied. It will be particularly noted that the stator and rotor plates are concentrically symmetrically arranged, whereby a high degree of compactness is afforded, the rotor requiring a minimum of space for its path of travel, so that the cover Zil becomes practical to apply. Heretofore, condensers arranged to change the capacity thereof at variable rates have been arranged with the condenser plates disposedaccording to an eccentric principle, so that the rotor requires a higher path of travel and therefore more space in a radio apparatus,

; and hence such condensers were not provided with a cover.

For mounting the stator plates, the same may be formed with arcuate segments 27! which may be suitably secured to the angular plates 2%. in

30, order to insulate the stator from the frame, the plates 28 may be engaged with plates of insulation 29, as by screws 30, and terminal contacts 3!! may i also be amxed to said screws. In the opposed side frame sections l5, openings 32 may be provided.

Along the upper and lower edges of said openings, lugs 33 may be pressed inward and with their ends slightly toward each other, and along the side edges of said openings, lugs 3t may be pressed inward and curved to afford an entrance. In pro-- viding lugs 33, flanges 35 may be formed along the upper and lower edges of said openings. The

plates 29 are snugly fitted in seating engagement between the several lugs 33, 3d and so as to rest against the flanges 35, being so maintained by reason of the abutment action of the stator and plates 28 between the opposite insulating plates 29. The plates 2t may be slightly resilient if desired to afford a snug wedging flt. Heretofore the plates 29 have been riveted to the frame.

50. This required the use of non-brittle materials of low insulating qualities. By my invention, the

' expense of riveting is avoided, and plates as of high insulating character may be employed, which are reliantly and quickly secured in place.

For mounting the rotor plates 26, a means 36 may be provided which may in certain respects be denominated a shaft, and in other respects a frame or plate. The same may have rib or flange means 31, and is desirably made of channel form in cross'section, and is preferably made of a sheet of material such as metal. Thus a sheet of plane material may be bent and slotted in a single operation to produce the means 36. One possible embodiment of the invention, preferably includes the flange and channel features, the latter being designated by 38, and including a baclr. 39 and side walls or flanges 40 from which one or more of the marginal lips or flanges 31' extend radially, as along a plane passing through the axis of rotation of the shaft. -The back 39 may be transversely slotted as at 4 l ,and the flanges 3! may have slots 42 alined with different slots H, the slots 42 extending preferably to the side walls of the channel. Intermediate of the ends of the shaft, the flanges 31 may be cut away as at it, if. d sired.

access-s to afford clearance for the intermediate plate at an opening 44 thereof which may form a part of a slot 45 that clears the shaft so that the rotor unit can be dropped into the frame to be assembled therein. 5

By means of the lips 317, the rotor plates are reenforced along a greater length, and increased rigidity thereof is obtained.

For fixing the rotor plates to the shaft, each rotor plate may have an opening 46 adapted to 10 receive the shaft and having edge portions Q7? and it at said opening fitted in the respective slots (it, AlZof the shaft and bearing against the side walls of the channel shaft section. For stron ly securing the rotor plates in the slots, a force may be exerted on the outside of the back of the channel between the different rotor plates, and if desired, the flanges 3'17 may be deformed slight- 1y, whereby the metal between the different slots 3 0, d2 is caused to tightly pinch and permanently 20 hold the rotor plates.

For mounting the shaft 36, any suitable means may be employed, and preferably said shaft is provided with integral tongues 49, 5d at opposite ends thereof, and which may extend from the 25 back of the channel structure. Said tongues may be bent as at 5i so as to lie in square abutment with the ends of the side walls or flanges 40 of the channel structure. To afford frictionless bearing means for the shaft, the elements 49, 5t 30 may be formed with alined openings or recesses 52-.that open outwardly in opposite directions to afford seats for hearing members such as antifriction balls 53, the end walls ii, if having means affording corresponding alined seats for 85.

is utilized. The same may have an eye 5Q pressed therefrom and fitted in a corresponding hole in the end plate ii. One end portion of the spring may have a fork 60 taking about an adjacent ball 53 and bent laterally so that the end of the fork presses against the end plate ii, and another part of the fork presses against the end wall 49 of the shaft 36. The other end of the leaf spring is formed with a terminal hole 6i and projects beyond the end wall Ii, the cover 20 having an 55 open ended slot 62 for receiving the same. The spring 58 also serves to reduce any-possible axial "movement of the rotor, and facilitates the adjustment setting of the device at the screw 55.

It will be appreciated that according to my 60 invention both bearings for the shaft are simple, compact, and similar in construction. I

To provide a simplified means for causing angular movement of the shaft 36, the tongue 56 may be sufliciently elongated to constitute a crank 65 arm; The latter may. have a crank pin 63 extending through an opening or arcuate slot 64 in the front plate l2. The slot '64 is so arranged that the ends thereof afford stops for the pin 63 in the position of maximum capacity of the con- 70 denser shown in Fig. 1, and in the position of zero capacity of the condenser. Hence the stop engagement heretofore used for the condenser rotor plates directly is eliminated, and any strain taken up solely by the shaft. It will be noted that the crank 50 may extend in parallelism with the straight edges of the rotor plates.

To actuate the pin 63, a cam means 66 is preferably provided. The same may for compactness consist of a sheet of plane material parallel to the wall I2, and may desirably be fixed upon a sleeve 61, which may be journaled upon a bar or stub shaft 68 secured to the. wall l2, as at 69, in spaced relation to the axis of the shaft 36. To the sleeve 61, a conventional manual control knob and a dial with uniform graduations, not shown, maybe removably fitted in any well known manner. To provide for removability and interchangeability of the cam 66, the outer end of the stub shaft 68 may have an annular groove I0, and a washer 1 I, slotted at 12, may be removably snugly engaged therein to slidingly abut the end of the sleeve 61.

The cam means 66 may include an open ended fork 13 for slidingly receiving the pin 63. This fork may have any desired cam slope 14. To avoid backlash in the cam engagement, an opening 15 may be formed spaced from the closed end of the fork and connected therewith by a narrow opening 16, whereby the prongs of the fork are resiliently movable toward each other for snugly engaging the pin 63.

It will be appreciated that various changes and modifications may be made in the device as shown in the drawing, and that the same is submitted in an illustrative and not in a limiting sense, the scope of the invention being defined in the following claims.

I claim:

1. A variable condenser including a rotor condenser plate, and a shaft of sheet metal of substantially channel shape, said shaft having longitudinal integral radial lips extending along the flanges of the channel, said channel having a transverse slot in the back thereof and alined slots in said lips, and said rotor plate being fitted in said slots for mounting on the shaft.

2. A variable condenser including a stator plate, a rotor plate, a shaft on which the rotor plate is mounted for angular movement, a frame having opposed frame members, said frame members having openings therein, flanges along the edges of said openings, laterally bent spaced lugs at the edges of said openings, plates of insulation within the frame at said openings fitted between said lugs and resting against said flanges, means for mounting the stator plate on said plates of insulation so as to maintain the latter in engagewhereof are provided with longitudinally extending marginal lips projecting in different directions away from each other, said lips having alined transverse slots and said shaft having another part provided with a transverse slot alined with the first mentioned slots, and the rotor plate being secured in said slots, whereby the portion of the rotor plate adjacent-to said shaft is rigidly held substantially throughout, as set forth.

4. A variable condenser including a rotor condenser plate, and a channel shaft having a back having a transverse slot, said channel shaft having a flange provided with a longitudinal marginal lip having a transverse slot, said lip projecting outwardly and laterally of said flange, and the rotor plate being fitted in said slots, as set forth.

5. A variable condenser including a stator plate, a rotor plate, a shaft on which the rotor plate is mounted for angular movement, a frame having opposed frame members, said frame members having openings therein, flanges along the edges of said openings, laterally bent spaced lugs at the edges of said openings, plates of insulation within the frame at said openings fitted between said lugs and resting against said flanges, means for mounting the stator plates on said plates of insulation, as set forth.

6. In a variable condenserin combination a plurality of rotor plates each having a hub receiving depression and having projecting tongues on opposite sides thereof and at the bottom thereof, a hub formed by a comb of strip material bent to substantially U shape, and having oppositely extending wings having openings therein to receive said tongues, whereby said plates are secured to said comb, and said comb having ears at opposite ends thereof folded upwardly to define a trough, said hub-plate assembly being supported by said ears.

7. A device including a channel member, a plate secured to the back thereof, the channel member having a lip extending along a flange thereof, said lip having a transverse slot open ended at the free edge of the lip, and said plate being additionally secured to the channel member in said slot.

8. In a variable condenser, a plate, and a shaft of sheet metal of substantially channel shape providing longitudinal flanges, one of the latter having an outward extending marginal lip, said lip and the back of the channel having transverse elongated narrow openings at one side of the shaft, said plate being clampingly secured in said openings.

JOSEPH ANTONIE'I'IA. 

